1) Because I've tried it.
I had the rollback to 1.6 applied when it first was released to Apple Stores. This resolved the frequent and annoying freezing I was seeing (video). Today, upon hearing of the new update… I re-updated to EFI 1.7… verified the issue was there… applied the "Performance Update 1.0"… verified the issue was still there… have scheduled another firmware rollback for tomorrow.
2) Because it's an OS update, not a firmware update. An OS update will do nothing to resolve hardware interface issues that also show themselves with other OSes -- and people have seen this SATA II interface issue with Windows, Linux, etc. running on their MBPs.
The update appears to have resolved some beachballing issues that people have been having, but it does not address this issue with the SATA II interface implementation in EFI 1.7 firmware.
1) Yes it does, makes the issue better for me. Since EFI 1.7 I been getting alot of beachballs, especially when doing alot at the same time (torrent + certain videos + firefox is a sure way to get em within a few minutes). Yesterday I got the beachballs every 9 minutes in a movie. But since this update instead of the whole computer locking up and beachballing, instead the program which causes the problem locks up (so if I watch a movie the movie freezes, but I dont get a system wide beachball anymore, so I can still surf the web/type in firefox)
And yeah, im on a X25-M drive.
2) That's not really true, a OS update can ofcourse make it better. The OS handles how to push the data, so ofc you can change the way the OS interacts with the hardware...